Penentuan parameter persamaan konstitutif baja HSLA (ASTM A572 Grade 50) dengan uji tarik panas
| Main Author: | Diwangkoro Kingkin, author |
|---|---|
| Format: | Bachelors Thesis |
| Terbitan: |
Fakultas Teknik Universitas Indonesia
, 2011
|
| Subjects: | |
| Online Access: |
http://lib.ui.ac.id/file?file=digital/20282016-S694-Penentuan parameter.pdf |
Daftar Isi:
- [<b>ABSTRAK</b><br> Mampu bentuk (formability) material bukan hanya ditentukan oleh mikrostruktur dari material, temperatur, laju regangan (strain rate) dan regangan (strain), tetapi juga tahapan tegangan pada zona deformasi. Uji tarik panas merupakan salah satu metode pengujian yang dilakukan untuk mengevaluasi sifat mekanis dari material, memperoleh informasi plastisitas material dan sifat perpatahan (fracture). Pengujian dilakukan dengan menggunakan parameter dari persamaan konstitutif dimana tegangan alir merupakan fungsi dari regangan, laju regangan dan temperatur. Hal ini dapat menjelaskan karakteristik Rheologi dari material tersebut. Penelitian ini bertujuan untuk mempelajari karakteristik Rheologi dari material baja HSLA (ASTM A572 Gr 50) dengan menentukan parameter persamaan konstitutif menggunakan uji tarik panas, dengan variabel temperatur 700 oC, 750 oC, 800 oC, dan 850 oC. Dalam penelitian ini dapat dihasilkan parameter persamaan konstitutif untuk paduan Baja HSLA (ASTM A572 Gr 50), yaitu σ = K. ɛn. έm. eQ /RT, di mana dengan meningkatnya temperatur dari 700 0C ke 800 0C akan menurunkan nilai koefisien pengerasan regang (n) sebesar 47% dan menurunkan % elongasi sampel sebesar 26%. Pada laju regangan 0.1 s-1 dengan meningkatnya temperatur dari 700 0C ke 850 0C akan menurunkan tegangan luluh sebesar 42%. Pada laju regangan 0.1 s-1 dengan meningkatnya temperatur dari 750 0C ke 850 0C, akan meningkatkan nilai koefisien sensitifitas laju regangan (m) sebesar 96%. Pada temperatur konstan 850 0C , dengan meningkatnya laju regangan dari 0.01 s-1 ke 0,1 s-1 akan menurunkan nilai energi aktivasi sebesar 2%. <hr> <b>ABSTRAK</b><br> Formability not only determined by the microstructure of the material, temperature, strain rate and strain, but also stage the voltage on the deformation zone. Hot tensile test one method of testing conducted to evaluate the mechanical properties of the material, information material plasticity and fracture properties. Tests carried out by using the parameters of constitutive equations in which the flow stress is a function of strain, strain rate and temperature. This may explain the rheological characteristics of the material. This research aims to study the rheological characteristics of HSLA steel material (ASTM A572 Gr 50) by determining the parameters of the constitutive equation using hot tensile test, with variable temperature 700 0C, 750 0C, 800 0C and 850 0C. In this study the constitutive equation can be generated parameters for HSLA steel alloy (ASTM A572 Gr 50), namely σ = K. ɛn. έm. eQ / RT, where with increasing temperature from 700 0C to 800 0C will lower the value of strain hardening coefficient (n) by 47% and lower % elongation of 26% of samples. At the strain rate 0.1 s-1 with increasing temperature from 700 0C to 850 0C will lower the yield stress by 42%. At the strain rate 0.1 s-1 with increasing temperature from 750 0C to 850 0C, will increase the value of strain rate sensitivity coefficient (m) of 96%. At a constant temperature of 850 0C, with increasing strain rate from 0.01 s-1 to 0.1 s-1 would lower the activation energy value of 2%. , Formability not only determined by the microstructure of the material, temperature, strain rate and strain, but also stage the voltage on the deformation zone. Hot tensile test one method of testing conducted to evaluate the mechanical properties of the material, information material plasticity and fracture properties. Tests carried out by using the parameters of constitutive equations in which the flow stress is a function of strain, strain rate and temperature. This may explain the rheological characteristics of the material. This research aims to study the rheological characteristics of HSLA steel material (ASTM A572 Gr 50) by determining the parameters of the constitutive equation using hot tensile test, with variable temperature 700 0C, 750 0C, 800 0C and 850 0C. In this study the constitutive equation can be generated parameters for HSLA steel alloy (ASTM A572 Gr 50), namely σ = K. ɛn. έm. eQ / RT, where with increasing temperature from 700 0C to 800 0C will lower the value of strain hardening coefficient (n) by 47% and lower % elongation of 26% of samples. At the strain rate 0.1 s-1 with increasing temperature from 700 0C to 850 0C will lower the yield stress by 42%. At the strain rate 0.1 s-1 with increasing temperature from 750 0C to 850 0C, will increase the value of strain rate sensitivity coefficient (m) of 96%. At a constant temperature of 850 0C, with increasing strain rate from 0.01 s-1 to 0.1 s-1 would lower the activation energy value of 2%. ]